The minimum participant per arm was calculated to be 50 in order to detect reduction of fever for at least 12 hrs, with the standard deviation of 18, and α and β values set at 0.05. However, the sample size will be increase by 10% in order to take account of individuals lost of follow-up. Therefore the total number of participants to be enrolled in this study is estimated to be at least 180 with 60 participants per treatment arm.